FIG. 1 is a diagram illustrating a signal flow for a random access-based uplink Bandwidth Request (BR) procedure of an MS in a broadband wireless access system.
Referring to FIG. 1, a Base Station (BS) supports both a 5-step regular access procedure (steps 110 to 150) and a 3-step quick access procedure (steps 110, 140 and 150). The 5-step regular access procedure may be used independently of the 3-step quick access procedure or a fallback for the 3-step quick access procedure.
In the 3-step quick access procedure, the MS transmits a BR indicator including an MS Identifier (ID), information about a requested bandwidth, etc. to the BS in step 110. Upon receipt of the BR indicator, the BS allocates UL resources to the MS in step 140. In step 150, the MS transmits data in the allocated UL resources. The MS may also transmit additional UL BR information.
In the 5-step regular access procedure, the MS transmits a BR indicator in step 110. Upon receipt of the BR indicator, the BS allocates UL resources for transmission of a BandWidth REQuest (BW-REQ) message to the MS in step 120. In step 130, the MS transmits the BW-REQ message using the allocated UL resources. Upon receipt of the BW-REQ message, the BS allocates UL resources to the MS in step 140 and the MS transmits data via the allocated UL resources in step 150. The MS may also transmit additional UL BR information.
The MS transmits UL request information such as an MS ID, a requested bandwidth, etc. to the BS using a BR indicator in the broadband wireless access system. The MS may also notify the BS of rough information about the Quality of Service (QoS) level of data to be transmitted. Table 1 below illustrates an example of QoS level information to be transmitted in the BR indicator.
TABLE 1QoS levelService TypeContention-based reservation timeout1Real-time502Real-time903Real-time1304Non-real-time200
Because essential UL request information may vary depending on the operation mode of the MS (i.e. non-contention/contention mode), it may be inefficient to transmit UL request information in the same format with no regard to the operation mode.